Fascioloides magna (Trematoda) and Taenia hydatigena (Cestoda) from white-tailed deer

Livers of 164 white-tailed deer (Odocoileus virginianus) from the Peterborough Crown Game Preserve in central Ontario were examined for Fascioloides magna and Taenia hydatigena. Fascioloides magna was recovered from 2.6% of fawns and 68.3% of all older deer, and mean intensity of infection increased with age. Both prevalence and intensity of unencapsulated flukes were similar among all age-groups of deer 1 year of age and older. While the majority (96%) of encapsulated flukes were within capsules containing more than one fluke, aggregation of flukes is probably not required for either encapsulation or maturation. Infection with F. magna had no detectable effect on the condition of yearling or adult male deer, where condition was measured by depth of fat on the rump and sternum. Cysticerci of T. hydatigena were most prevalent among yearlings (70%) as compared with all other age-groups (29%). Mean intensity of infection with T. hydatigena tended to increase with age.